1. Field of the Invention
In homogeneous enzyme immunoassays, as described in U.S. Pat. No. 3,817,837, one normally measures the change in level of the detectible signal over a predetermined relatively short time period. In many situations, it is desirable to be able to quench the reaction at the end of the predetermined interval and measure the result subsequently at one's leisure. However, the manner in which the enzyme reaction is quenched is subject to many constraints. First, the reaction must be stopped completely. One cannot allow for a slow continuous reaction, since the measurement would then become time dependent. Secondly, the manner in which the reaction is terminated must not affect the stability of the compound providing the detectible signal nor result in any transformation of the precursor which provides the product. Thus, where chemically labile compounds are involved in the production of the detectible signal, the nature of the quenching reaction is severely limited.
2. Description of the Prior Art
U.S. Pat. No. 3,817,837 describes a homogeneous enzyme immunoassay. Inhibition of enzymes by antibodies to enzymes is known. U.S. Pat. No. 3,654,090 is descriptive of heterogeneous enzyme immunoassays.